1. Investigation of Model Sunscreen Formulations Comparing the Sun Protection Factor, the Universal Sun Protection Factor and the Radical Formation Ratio
- Author
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Fanny Knorr, Sabine Schanzer, Jürgen Lademann, Martina C. Meinke, Felicia Syring, and H.-J. Weigmann
- Subjects
Adult ,Male ,Electron paramagnetic resonance spectroscopy ,Free Radicals ,Swine ,Ultraviolet Rays ,Physiology ,Infrared ,Analytical chemistry ,Iso standards ,Dermatology ,medicine.disease_cause ,Photochemistry ,01 natural sciences ,Antioxidants ,010309 optics ,Young Adult ,030207 dermatology & venereal diseases ,03 medical and health sciences ,0302 clinical medicine ,Sun protection factor ,0103 physical sciences ,medicine ,Animals ,Humans ,Radical formation ,skin and connective tissue diseases ,Skin ,Pharmacology ,Sunlight ,integumentary system ,Chemistry ,Spectrum Analysis ,General Medicine ,Erythema ,Female ,Sun exposure ,Sun Protection Factor ,Sunscreening Agents ,Ultraviolet - Abstract
In view of globally rising skin cancer rates and harmful effects exerted by sunlight throughout the ultraviolet, visible and infrared ranges, an objective, safe and comprehensive method for determining sunscreen efficacy is required in order to warrant safe sun exposure. In this study, the influence of characteristic active ingredients (chemical filters, physical filters and antioxidants) on different sunscreen indicators, including the universal sun protection factor and the radical formation ratio, was determined and compared to their influence on sun protection factor values. Spectroscopic universal sun protection factor measurements were conducted ex vivo by analyzing tape strips taken from human skin, and radical formation ratio determination was performed via electron paramagnetic resonance spectroscopy using porcine ear skin ex vivo. The sun protection factor determination was conducted according to ISO standards (ISO 24444:2010). It was shown that chemical filters provide a protective effect which was measurable by all methods examined (spectroscopy, electron paramagnetic resonance spectroscopy and erythema formation). Physical filters, when used as single active ingredients, increased protective values in universal sun protection factor and sun protection factor measurements but exhibited no significant effect on universal sun protection factor measurements when used in combination with chemical filters or antioxidants. Antioxidants were shown to increase sun protection factor values. Radical formation ratio values were shown to be influenced merely by chemical filters, leading to the conclusion that the universal sun protection factor is the most suitable efficacy indicator for the ultraviolet range.
- Published
- 2015